The prevalence of obesity and type 2-diabetes is increasing worldwide and threatens to shorten lifespan. Impaired insulin action in peripheral tissues is a major pathogenic factor. Insulin stimulates glucose uptake in adipose tissue through the Glut4-glucose transporter and alterations in adipose-Glut4 expression or function regulate systemic insulin sensitivity. Downregulation of adipose tissue-Glut4 occurs early in diabetes development. Complications from obesity and type-2 diabetes include vascular disease, which detracts from quality of life further and increases mortality. Other disorders, such as polycystic ovarian syndrome and some inflammatory disorders have higher prevalence in individuals with diabetes related disorders—and the signaling pathways driving certain diabetes related disorders cross-talk with pathways that regulate inflammation. In addition, cancer, a prevalent and devastating disorder can be characterized by changes in metabolic flux, e.g., via the so-called Warburg effect, by which cancer cells substantially upregulate the level of glycolysis. Many cancer cells also have increased de novo lipogenesis. In view of the prevalence of these disorders and their relation to changes in metabolism, a need exists for methods of detecting and monitoring disease states and/or treatment programs in subjects with diabetes-related disorders, obesity, polycystic ovarian syndrome (PCOS), gestational diabetes, inflammatory disorders, vascular disease, or cancer, as well as tools and method of identifying agents that modulate key metabolic pathways.